diff --git a/features/http-auth.xml b/features/http-auth.xml
index 41cbfd80f4..cc9e9a8e2b 100644
--- a/features/http-auth.xml
+++ b/features/http-auth.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.53 $ -->
+<!-- $Revision: 1.54 $ -->
  <chapter xml:id="features.http-auth" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
   <title>HTTP authentication with PHP</title>
 
@@ -105,8 +105,9 @@ function http_digest_parse($txt)
     // protect against missing data
     $needed_parts = array('nonce'=>1, 'nc'=>1, 'cnonce'=>1, 'qop'=>1, 'username'=>1, 'uri'=>1, 'response'=>1);
     $data = array();
+    $keys = implode('|', array_keys($needed_parts));
 
-    preg_match_all('@(\w+)=(?:([\'"])([^\2]+)\2|([^\s,]+))@', $txt, $matches, PREG_SET_ORDER);
+    preg_match_all('@(' . $keys . ')=(?:([\'"])([^\2]+?)\2|([^\s,]+))@', $txt, $matches, PREG_SET_ORDER);
 
     foreach ($matches as $m) {
         $data[$m[1]] = $m[3] ? $m[3] : $m[4];